The Sandy Weill story is truly one for the ages. Starting with $30,000 in borrowed cash in 1960, and relying on uncanny entrepreneurial instincts in the corporate world, he made himself a billionaire and became one of the most powerful bankers in the world. After rising to become the president of American Express, Weill saw his empire crash and burn. Undaunted, he started over and eventually became CEO and then chairman of Citigroup.